1. Field of the Invention
The present invention relates to an improvement in a oven having a broiler type heater element.
2. Description of the Prior Art
A conventional broiler oven is known that has a structure as shown in FIG. 15. This oven cooks food to be cooked 8 placed on a turntable 5 by applying thereto microwaves produced by a magnetron (not shown) within a heating chamber 2 provided inside a cabinet 1 openable with a door 1a, or heat radiated from an upper fixed heater 3 provided in the ceiling 2a of the heating chamber 2 and from a lower fixed heater 4 provided in the floor 2b of the heating chamber 2. Another conventional broiler oven is known that has a structure as shown in FIG. 16. This oven has, instead of the upper fixed heater 3 of the above conventional broiler oven, a movable heater 6, formed out of a tubular heater, in the upper portion of the heating chamber 2, so that, when food to be cooked 8 placed on the turntable 5 is cooked, heat can be applied thereto with the movable heater 6 rotated downward.
As shown in FIG. 17, the movable heater 6 of the latter conventional broiler oven is formed, as a whole, to have a U-shaped horizontal section. The two open-side ends of the movable heater 6 are both bent outward so as to form a shaft portion 6a, and are rotatably supported by the upper portion of the side walls of the heating chamber 2. The free, closed-side portion of the movable heater 6 is formed in a shape of a series of alternating U-shaped turns so as to form a heating portion 6b. To this heating portion 6b, a reflecting plate 7 (see FIG. 16) is attached so that the heat radiated from the heating portion 6b will be reflected efficiently toward the food to be cooked 8.
Moreover, the movable heater 6 of the latter conventional broiler oven has its shaft portion 6a driven by a driving mechanism 12 provided on the outer surface of the upper portion of either of the side walls of the heating chamber 2. In accordance with how data entry keys 9 provided on an operation panel are operated, a control circuit 10 controls the driving mechanism 12 to rotate the movable heater 6 between a resting (non-heating) position indicated by solid lines in FIG. 16 and a heating position indicated by broken lines.
In a broiler oven having a heater, it is customary to use a grill as shown in FIG. 18 as a cooking rack. Such a grill 11 is composed of a frame 11a made by forming a metal or other wire into a flat rectangular, and a plurality of parallel metal or other beams 11b fitted thereto uniformly from above or below at regular intervals so as to bridge between the two longer sides of the rectangular. As shown in FIGS. 19 and 20, the grill 11 is placed on grill brackets 2c provided on the inner surfaces of the side walls 2e of the heating chamber 2, and is used for oven-like heating with food to be cooked 8, such as a slice of bread to be toasted or a piece of frozen pizza to be thawed, placed on the grill 11.
However, in the broiler oven shown in FIG. 15, the upper fixed heater 3 is placed too far away from the food to be cooked 8, and thus heating the food 8 as desired requires too much time. On the other hand, in the broiler oven shown in FIG. 16, when the movable heater 6 is rotated to the heating position so as to be brought closer to the food to be cooked 8, its heating portion 6b, which is flat, is inevitably held in a inclined posture with respect to the food 8, and this leads to uneven cooking of the food 8.
Moreover, when the grill 11 is used, the food to be cooked 8 may be placed at different levels depending on whether the grill 11 is placed on the grill brackets 2c of the heating chamber 2 with the beams 11b located above the frame 11a as shown in FIG. 19 or with the beams 11b located below the frame 11a as shown in FIG. 20. This causes variation in the distance from the heater to the food 8, and thus leads to uneven cooking of the food 8.